1. Field of the Invention
The present invention relates to electric power source devices equipped with a transformer.
2. Description of the Related Art
An electric power source device such as a direct current to direct current (DC-DC) converter has a transformer, a choke coil, various types of electronic components etc. Further, the electric power source device is equipped with a circuit substrate which forms a control circuit and some of a main circuit. For example, a patent document 1, Japanese patent laid open publication No. 2013-34270, discloses an electric power source device having a structure in which a circuit substrate having a large area is arranged in the inside of a housing.
A recent technique provides an electric power source device having a miniaturized structure accompanied with downsizing of each of a transformer, a choke coil and other electronic components. However, it is difficult to perform downsizing of the circuit substrate when compared with the downsizing of other components because the circuit substrate has a wide area which expands in 2 dimensions. The recent trend of downsizing of the electric power source device causes a difficulty of correctly arranging the circuit substrate in a miniaturized size. In other words, it becomes difficult to reduce an overall size of the electric power source device because of having the circuit substrate.